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Health

What you need to know as the Omicron BA.5 subvariant drives cases up

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Ontarians are being told to get up to date on their COVID shots as a summer wave fuelled by the Omicron BA.5 subvariant has likely begun.

It’s a particularly important message in Hamilton where booster uptake has been sluggish.

“The third vaccine dose is critical to protect against severe disease,” stated an advisory Wednesday by Ontario’s COVID-19 Science Advisory Table.

Its message to the public provides a guide of what Ontarians need to know about the seventh COVID wave.

Has a new wave started?

The science table declared a likely new wave on Wednesday. On the same day, Hamilton public health reported COVID transmission was increasing for the first time since April.

Both look to a number of measures, including rising wastewater samples with COVID-19 detected.

The number of tests coming back positive is above 10 per cent provincially for the first time since May. For Hamilton, it went up to an average of nearly nine per cent on June 30 from six per cent on June 16.

About 80 per cent of public health units are seeing exponential growth in cases. In Hamilton, average daily new cases were up to 62 on July 3 from 25 on June 6. Cases are a significant underestimate.

What is driving the wave?

Highly-contagious Omicron subvariants, particularly BA.5, are fuelling the summer wave.

“You can be reinfected by BA.5 even if you have recently been infected with an earlier strain,” stated the science table.

However, it doesn’t cause more serious illness.

“Current evidence does not suggest BA.5 is more severe or that it will lead to a rise in hospitalizations as large as previous waves,” stated the science table.

What if I get infected?

“Infections can leave you feeling unwell, and be disruptive to your family and work life,” stated the science table. “Each infection puts you at risk of long COVID.”

While the risk of severe illness isn’t higher with BA.5, it’s also not zero. The science table reported the first increase in COVID hospitalizations since May.

“If BA.5 spreads widely, we may see a rise in deaths among higher risk groups,” stated the science table.

What about the health-care system?

“Hospitals are already very strained,” warned the science table. “Any surge comes at a time when hospitals are already dealing with staff shortages and record wait times — this impacts all of us.”

Hamilton’s hospitals had 700 job openings they couldn’t fill as of May and 292 staff self-isolating as of Wednesday.

In addition, overcrowding on the wards and high numbers of patients coming to the emergency departments have resulted in ambulances waiting hours to off-load patients, causing a spike in “Code Zero” events in June. Code Zero is when one or no ambulances are available to respond to emergencies.

Hamilton’s hospitals also have pandemic backlogs they are trying to clear, including nearly 15,000 surgeries as of March.

At the same time, there are still COVID patients being admitted.

“Hospitalizations remain higher than at any time last summer,” stated the science table.

Do I need to wear a mask?

“Going back to wearing a mask again in crowded indoor public spaces is a good way to protect yourself until the wave is done,” stated the science table.

Hamilton public health also “strongly recommends wearing a well-fitting mask indoors, especially when it’s crowded.”

The science table suggested a high-quality surgical mask, KN95 or N95.

“Ventilate as much as possible by opening windows and doors,” stated the science table. “Choose lower risk alternatives — for example, enjoy the great weather by gathering with friends outdoors instead of indoors.”

You can still enjoy the summer while reducing your risk of getting COVID, urged the science table.

“Unfortunately, a recent infection may not protect you very well from reinfection with BA.5,” it stated. “So, as we’re entering a new wave, it’s worth re-engaging with multiple layers of protection to reduce risk.”

Does a booster make a difference?

“Ensure your vaccinations are up to date,” stated the science table. “It provides significant additional protection against serious illness.”

Hamilton data shows the staggering difference COVID shots make. The unvaccinated have a hospitalization rate of 434.1 per 100,000 population compared to 75.8 for those with three shots. The risk of being admitted to the intensive care unit is 12 times higher for the unvaccinated than the boosted.

But coverage remains low, with fewer than 50 per cent of Hamiltonians age 18 to 39 boosted. Coverage for kids is even worse, with only 17 per cent of those age 12 to 17 having three shots.

“New vaccines targeted to emerging variants could be available this fall, but as there’s a wave starting, it makes sense to get the vaccines you are eligible for now,” stated the science table. “If you are age 60 or over, or immunocompromised, and haven’t received your 4th dose, now is the time.”



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What the BA.5 Subvariant Could Mean for the United States

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The most transmissible variant yet of the coronavirus is threatening a fresh wave of infections in the United States, even among those who have recovered from the virus fairly recently.

The subvariant of Omicron known as BA.5 is now dominant, according to federal estimates released Tuesday, and together with BA.4, another subvariant, it is fueling an outbreak of cases and hospitalizations.

United States

Est. share of cases from Omicron variants

Jan. 1

July 4

50%

100%

BA.1

BA.2

BA.4

BA.2.12.1

BA.5

New cases per 100,000 people

Jan. 1

July 4

100

200

BA.5

Sources: CoVariants.org; GISAID; New York Times database of cases and deaths | Note: Charts show 14-day case averages, and the frequency of variants among cases is an estimate. Sequencing rates can reflect localized trends based on testing from a particular region or hospital. Charts show the latest available data, which may be lagged and may change as additional sequences are completed. Recent data is based on the smallest samples and is especially likely to change.

Though the popularity of home testing means reported cases are a significant undercount of the true infection rate, the share of tests that come back positive is shooting upward and is now higher than during most other waves of the pandemic. According to the C.D.C., the risk from Covid-19 is increasing in much of the country.

“I think there’s an underappreciation of what it’s going to do to the country, and it already is exerting its effect,” said Eric Topol, a professor of molecular medicine at Scripps Research, who has written about the subvariant.

BA.5 and BA.4, both subvariants of the Omicron variant that swept the world during the winter, are the most capable versions of the virus yet at evading immunity from previous infections and vaccines. Both variants have mutations in their spike proteins that are different enough from earlier versions of the virus that they are able to dodge some antibodies.

Waves of infection — and the subsequent immunity that comes with them — vary across countries and make for imperfect comparisons. Vaccination rates also vary. But in places where BA.4 and BA.5 have been dominant for weeks or months, the subvariants have caused increases in cases and hospitalizations, despite some population immunity from previous waves.

Covid-19 hospitalizations per 100,000 people

South Africa

Jan. 1

July 4

25

50

BA.4+BA.5

dominant

Sources: Our World in Data, CoVariants.org, Centers for Disease Control and Prevention, U.S. Department of Health and Human Services. | Note: Time periods of BA.4 and BA.5 becoming dominant are estimates.

The C.D.C. says there is so far no evidence that BA.4 or BA.5 is inherently more severe than other Omicron subvariants, but when more people become infected, the number of people hospitalized because of the virus may also rise.

Prior infection with another form of the Omicron variant does confer some degree of immunity, Dr. Topol said, and that may explain why cases have not yet taken off sharply in the United States. “But it’s not anything like what we would hope,” he said. Omicron subvariants appear to represent a departure from earlier waves of the virus, when prior infection was more likely to protect against reinfection.

In Portugal, where vaccination rates are higher than in the United States, cases rose sharply after BA.5 became dominant in May, and hospitalizations neared their previous Omicron peak.

Portugal

Est. share of cases from Omicron variants

Jan. 1

July 4

50%

100%

BA.1

BA.2

BA.5

NO
SEQUENCING
DATA

New cases per 100,000 people

Jan. 1

July 4

200

400

NO
SEQUENCING
DATA

Sources: CoVariants.org; GISAID; New York Times database of cases and deaths | Note: Charts show 14-day case averages, and variant frequencies are estimates from CoVariants, binned in two-week intervals. Sequencing can reflect localized trends based on testing from a particular region or hospital. Charts show the latest available data, which may be lagged and may change as additional sequences are completed. Recent data is based on the smallest samples and is especially likely to change.

Before BA.4 and BA.5 became dominant in South Africa in April, research suggested that 98 percent of the population had some antibodies from vaccination or previous infection or both.

Even with those protective antibodies, many people in the country still became infected with BA.4 and BA.5, and the subvariants caused a small increase in cases, hospitalizations and deaths.

South Africa

Est. share of cases from Omicron variants

Jan. 1

July 4

50%

100%

BA.1

BA.2

BA.4

BA.5

NO
SEQUENCING
DATA

New cases per 100,000 people

Jan. 1

July 4

25

50

NO
SEQUENCING
DATA

Sources: CoVariants.org; GISAID; New York Times database of cases and deaths | Note: Charts show 14-day case averages, and variant frequencies are estimates from CoVariants, binned in two-week intervals. Sequencing rates can reflect localized trends based on testing from a particular region or hospital. Charts show the latest available data, which may be lagged and may change as additional sequences are completed. Recent data is based on the smallest samples and is especially likely to change.

Places just emerging from significant spring waves of the virus may not be spared, either. Several countries in Europe had big outbreaks of a different Omicron subvariant, BA.2, that led to new waves of hospitalizations and deaths that peaked as recently as April. Yet in those countries, cases are ticking up again as BA.5 becomes dominant.

United Kingdom

Est. share of cases from Omicron variants

Jan. 1

July 4

50%

100%

BA.1

BA.2

BA.5

NO
SEQUENCING
DATA

New cases per 100,000 people

Jan. 1

July 4

100

200

NO
SEQUENCING
DATA

France

Est. share of cases from Omicron variants

Jan. 1

July 4

50%

100%

BA.1

BA.2

BA.5

NO
SEQUENCING
DATA

New cases per 100,000 people

Jan. 1

July 4

200

400

NO
SEQUENCING
DATA

Italy

Est. share of cases from Omicron variants

Jan. 1

July 4

50%

100%

BA.1

BA.2

BA.5

NO
SEQUENCING
DATA

New cases per 100,000 people

Jan. 1

July 4

100

200

NO
SEQUENCING
DATA

Sources: CoVariants.org; GISAID; New York Times database of cases and deaths | Note: Charts show 14-day case averages, and variant frequencies are estimates from CoVariants, binned in two-week intervals. Sequencing rates vary between countries and sometimes reflect localized trends based on testing from a particular region or hospital. Charts show the latest available data, which may be lagged and may change as additional sequences are completed. Recent data is based on the smallest samples and is especially likely to change.

Experts say it is too early to fully predict what the latest subvariants may bring to the United States, which had an even more recent virus wave in May and June, driven by both BA.2 and yet another subvariant called BA.2.12.1. High shares of recent infections from BA.2.12.1 like that in the United States were uncommon among the countries now experiencing waves of BA.4 and BA.5 infections.

The United States also has a lower vaccination rate than many of those countries, and a much lower share of seniors who have had one or both booster shots.

“There’s a wave afoot, there’s no question about it,” Dr. Topol said. “My concern is the length of it.”

Tracking the Coronavirus


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Health

Why UCSF’s Bob Wachter says COVID variant BA.5 is ‘a different beast’

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The new BA.5 strain of the COVID-causing virus is “a different beast” from ones we’ve already seen — more infectious and better able to evade immune responses — and “we need to change our thinking” about how to defend against it, according to a data-packed Twitter thread posted today by Dr. Bob Wachter, UCSF’s chair of medicine.

BA.5, a sub-variant of the Omicron family which has an altered version of the virus’s infamous “spike” protein, will soon become the dominant strain of the virus in the U.S., meaning that “its behavior will determine our fate for the next few months, until it either burns itself out by infecting so many people or is replaced by a variant that’s even better at infecting people,” Wachter wrote.

“Neither is a joyful scenario,” he added.

The number of new COVID cases per day has plateaued nationally and is down significantly since January. The same is true for the number of COVID hospitalizations in the UCSF health system, Watchter said. However, the true spread of COVID is harder to know these days, because so many people are testing themselves with at-home kits.

And BA.5 could cause a continued plateau, or even a new surge of infections and possibly hospitalizations, because it infects more easily and also is better at evading immune responses — even in vaccinated people, Wachter wrote.

While he stressed that vaccines and vaccine booster shots “remain hugely valuable in preventing a severe case” that might lead to hospitalization or death, the increased slippieriness of BA.5 means that existing vaccines will probably be less effective at preventing mild COVID cases or stopping transmission in the first place. Also, he wrote, prior infection by a different variant “no longer provides robust protection from reinfection” with BA.5.

What should a person do, then?

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Wachter said it depends on how badly you want to avoid getting COVID. Personally, he said, he doesn’t want to risk getting “Long COVID” and the debilitating symptoms that come with it, “So I still avoid indoor dining & will continue to wear an N95 in crowded indoor spaces until cases come way down.” Others might make different choices.

As for governments, he said, if BA.5 causes a surge in hospitalizations, “particularly if we also have staff shortages,” a return to mask mandates “would be the right call.” But Wachter acknowledged there would likely be fierce resistance to new mask-wearing requirements, especially outside of blue states, regardless of the danger.

“Most people have ditched their masks,” he wrote.

Jason Fagone (he/him) is a San Francisco Chronicle staff writer. Email: jason.fagone@sfchronicle.com Twitter: @jfagone



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Omicron BA.5 & BA.4 Officially Dominant Covid Strains In U.S. – Deadline

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A little over a month after the more transmissible BA.2.12.1 Omicron subvariant became officially dominant in the U.S. on May 24, two sister subvariants of Omicron have quickly eclipsed BA.2.12.1 across the country.

BA.5 and BA.4 are, like BA.2.12.1, more transmissible, but have the added advantage of reportedly being more able to reinfect those who’ve already had Covid.

“We now report findings from a systematic antigenic analysis of these surging Omicron subvariants,” says a paper published last month to the BioRxiv preprint server. “BA.2.12.1 is only modestly (1.8-fold) more resistant to sera from vaccinated and boosted individuals than BA.2. On the other hand, BA.4/5 is substantially (4.2-fold) more resistant and thus more likely to lead to vaccine breakthrough infections.”


CDC

While BA.2.12.1 accounts for 42% of new cases this week, Centers for Disease Control and Prevention data shows that’s down from about 53% the week before. BA.5 and BA.4 by contrast have grown their shares from 25% and 12%, respectively, last week to about 37% and 16% this week. That means together the two variants which first emerged in South Africa earlier this year have jumped to a 55% share of all new cases in the last week.



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Covid: Omicron subvariants BA.4 and BA.5 escape antibodies from vaccination and prior infection, studies suggest

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However, Covid-19 vaccination is still expected to provide substantial protection against severe disease, and vaccine makers are working on updated shots that might elicit a stronger immune response against the variants.

“We observed 3-fold reductions of neutralizing antibody titers induced by vaccination and infection against BA4 and BA5 compared with BA1 and BA2, which are already substantially lower than the original COVID-19 variants,” Dr. Dan Barouch, an author of the paper and director of the Center for Virology and Vaccine Research at Beth Israel Deaconess Medical Center in Boston, wrote in an email to CNN.

“Our data suggest that these new Omicron subvariants will likely be able to lead to surges of infections in populations with high levels of vaccine immunity as well as natural BA1 and BA2 immunity,” Barouch wrote. “However, it is likely that vaccine immunity will still provide substantial protection against severe disease with BA4 and BA5.”

The newly published findings echo separate research by scientists at Columbia University.

They recently found that the BA.4 and BA.5 viruses were more likely to escape antibodies from the blood of fully vaccinated and boosted adults compared with other Omicron subvariants, raising the risk of vaccine-breakthrough Covid-19 infections.

The authors of that separate study say their results point to a higher risk for reinfection, even in people who have some prior immunity against the virus. The US Centers for Disease Control and Prevention estimates 94.7% of the US population ages 16 and older have antibodies against the coronavirus that causes Covid-19 through vaccination, infection, or both.
BA.4 and BA.5 caused an estimated 35% of new Covid-19 infections in the United States last week, up from 29% the week before, according to data shared by the US Centers for Disease Control and Prevention on Tuesday.

BA.4 and BA.5 are the fastest spreading variants reported to date, and they are expected to dominate Covid-19 transmission in the United States, United Kingdom and the rest of Europe within the next few weeks, according to the European Centre for Disease Prevention and Control.

‘COVID-19 still has the capacity to mutate further’

In the New England Journal of Medicine paper, among 27 research participants who had been vaccinated and boosted with the Pfizer/BioNTech coronavirus vaccine, the researchers found that two weeks after the booster dose, levels of neutralizing antibodies against Omicron subvariants were much lower than the response against the original coronavirus.

The neutralizing antibody levels were lower by a factor of 6.4 against BA.1; by a factor of 7 against BA.2; by a factor of 14.1 against BA.2.12.1 and by a factor of 21 against BA.4 or BA.5, the researchers described.

Among 27 participants who had previously been infected with the BA.1 or BA.2 subvariants a median of 29 days earlier, the researchers found similar results.

In those with previous infection — most of whom also had been vaccinated — the researchers described neutralizing antibody levels that were lower by a factor of 6.4 against BA.1; by a factor of 5.8 against BA.2; by a factor of 9.6 against BA.2.12.1 and by a factor of 18.7 against BA.4 or BA.5.

More research is needed to determine what exactly the neutralizing antibody levels mean for vaccine effectiveness and whether similar findings would emerge among a larger group of participants.

“Our data suggest that COVID-19 still has the capacity to mutate further, resulting in increased transmissibility and increased antibody escape,” Barouch wrote in the email. “As pandemic restrictions are lifted, it is important that we remain vigilant and keep studying new variants and subvariants as they emerge.”

A separate study, published in the journal Nature last week, found that Omicron may evolve mutations to evade the immunity elicited by having a previous BA.1 infection, which suggests that vaccine boosters based on BA.1 may not achieve broad-spectrum protection against new Omicron subvariants like BA.4 and BA.5.

As for what all this means in the real world, Dr. Wesley Long, an experimental pathologist at Houston Methodist Hospital, told CNN that people should be aware that they could get sick again, even if they’ve had Covid-19 before.

“I think I’m a little bit worried about people who’ve had it maybe recently having a false sense of security with BA.4 and BA.5 on the increase, because we have seen some cases of reinfection and I have seen some cases of reinfection with people who had a BA.2 variant in the last few months,” he said.

Some vaccine makers have been developing variant-specific vaccines to improve the antibody responses against coronavirus variants and subvariants of concern.

“Reinfections are going to be pretty inevitable until we have vaccines or widespread mandates that are going to prevent cases rising again. But the good news is that we are in, I think, a much better spot than we were without the vaccines,” said Pavitra Roychoudhury, an acting instructor at the University of Washington’s Department of Laboratory Medicine and Pathology, who was not involved in the New England Journal of Medicine paper.

“There’s so much of this virus out there that it seems inevitable,” she said about Covid-19 infections. “Hopefully the protections that we have in place are going to lead to mostly mild infection.”

Efforts underway to update Covid-19 vaccines

Moderna’s bivalent Covid-19 vaccine booster, named mRNA-1273.214, elicited a “potent” immune responses against the Omicron subvariants BA.4 and BA.5, the company said Wednesday.

This bivalent booster vaccine candidate contains components of both Moderna’s original Covid-19 vaccine and a vaccine that targets the Omicron variant. The company said it is working to complete regulatory submissions in the coming weeks requesting to update the composition of its booster vaccine to be mRNA-1273.214.

“In the face of SARS-CoV-2’s continued evolution, we are very encouraged that mRNA-1273.214, our lead booster candidate for the fall, has shown high neutralizing titers against the BA.4 and BA.5 subvariants, which represent an emergent threat to global public health,” Stéphane Bancel, chief executive officer of Moderna, said in Wednesday’s announcement. SARS-CoV-2 is the coronavirus that causes Covid-19.

“We will submit these data to regulators urgently and are preparing to supply our next generation bivalent booster starting in August, ahead of a potential rise in SARS-CoV-2 infections due to Omicron subvariants in the early fall,” Bancel said.

The US Food and Drug Administration’s Vaccines and Related Biological Products Advisory Committee is meeting next week to discuss the composition of Covid-19 vaccines that could be used as boosters this fall.

The data that Moderna released Wednesday, which has not been published in a peer-reviewed journal, showed that one month after a 50-microgram dose of the mRNA-1273.214 vaccine was administered in people who had been vaccinated and boosted, the vaccine elicited “potent” neutralizing antibody responses against BA.4 and BA.5, boosting levels 5.4-fold in all participants regardless of whether they had a prior Covid-19 infection and by 6.3-fold in the subset of those with no history of prior infection. These levels of neutralizing antibodies were about 3-fold lower than previously reported neutralizing levels against BA.1, Moderna said.

These findings add to the data that Moderna previously released earlier this month, showing that the 50-microgram dose of the bivalent booster generated a stronger antibody response against Omicron than the original Moderna vaccine.

Moderna’s data suggest that “the bivalent booster might confer greater protection against the BA.4 and BA.5 omicron strains than readministering the original vaccine to increase protection across the population. Although the information is based on antibody levels, the companies comment that similar levels of antibody protected against clinical illness caused by other strains is the first suggestion of an emerging ‘immune correlate’ of protection, although it is hoped that this ongoing study is also assessing rates of clinical illness as well as antibody responses,” Penny Ward, an independent pharmaceutical physician and visiting professor in pharmaceutical medicine at King’s College London, said in a statement released by the UK-based Science Media Centre on Wednesday. She was not involved in Moderna’s work.

“It has been reported previously that the bivalent vaccine is well tolerated with temporary ‘reactogenic’ effects similar to those following the univalent booster injection so we can anticipate that this new mixed vaccine should be well tolerated,” Ward said in part. “As we head towards the autumn with omicron variants dominating the covid infection landscape, it certainly makes sense to consider use of this new bivalent vaccine, if available.”

CNN’s Brenda Goodman contributed to this report.

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