Bracing Up For The Severity of BA.2 Wave In United States


According to a CNN analysis of federal data, as many as 28 million seniors are at risk of becoming severely ill from COVID-19, as a new version of the Omicron coronavirus variant is gaining traction in the United States, either because they are not vaccinated or partially vaccinated, or because it has been over five months since their second or third dose of a vaccine. Because the likelihood of problematic outcomes rises significantly with age, the immune status of people over 65 will be a key predictor of how subsequent variations will affect the US as it keeps a wary eye on rising instances induced by the BA.2 subvariant in Europe.

According to Stephen Kissler, a specialist in infectious disease modelling at Harvard’s TH Chan School of Public Health, the best criterion for how severe a given number of cases will end up being in terms of hospitalizations and deaths is to look at that older demographic and how much previous immunity they have, whether from older infection or vaccination.

The BA.2 subvariant of Omicron is growing roughly 80% faster as compared to BA.1, the infection that triggered the last surge of illnesses in the US over the winter, as per a study by the UK Health Security Agency. In the UK and many other European nations where BA.2 is becoming the prevalent strain, the number of instances and hospitalizations is on the climb.

Despite the fact that head-to-head comparisons with BA.1 demonstrate that BA.2 is not more likely to cause hospitalisation, this variant has the capacity to once again overload US health-care facilities if it finds enough vulnerable populations to infect.

Choosing not to use boosters

Adults over the age of 65 are by far the most susceptible, particularly those who have limited resistance to the virus.This is why Pfizer and BioNTech petitioned the USFDA to approve a fourth vaccine dose for older people last week. When it comes to the extremely critical and fatal diseases, it’s the group that’s the most challenging. It doesn’t mean that young people don’t end up in hospitals; it just doesn’t occur as frequently. At Columbia University’s Mailman School of Public Health, Jeffrey Shaman focuses on modelling the spread of infectious diseases.

Shaman gestures to Hong Kong, which is suffering from a devastating wave brought on by BA.2. It has the world’s highest COVID-19 mortality rate. And they haven’t experienced the full brunt of this because it takes quite a while, but that’s because they have an ageing population that wasn’t well-vaccinated.

Officials in the United States do not expect BA.2 to have the same impact in the United States as it did in Hong Kong. That’s due to the fact that the government has established a COVID zero-tolerance policy. Until recently, that policy has kept the number of cases and deaths low, making it a template for COVID management. But Omicron and BA.2 have vanquished such defences, infecting people who had never been exposed to the virus before.

Hong Kong used a somewhat different mix of vaccinations than the United States and Europe, including Sinovac injections developed in China and Pfizer’s Comirnaty.

Authorities are turning to the United Kingdom for signs about how BA.2 might act in the United States. However, they are not identical in every regard; for example, the UK has a higher innoculation rate. Overall, 82 percent of adults in the UK have had a third dose of the COVID-19 vaccine, which is critical for preventing Omicron infections and hospitalizations due to how “immune erosive” these versions are, according to Shaman. In the United States, this figure is only 36%. According to CDC data, 1 in 3 Americans over 65 years of age who are qualified for a booster dose have opted not to get a third injection, leaving roughly 15 million older Americans without such crucial extra protection.

Over time, protection wanes

Recent studies suggest that the timing of vaccines is also important. According to data obtained by the UK’s Health Security Agency, vaccine effectiveness for Omicron dropped to 10% for infections, 35% for hospitalizations, and 70% for deaths six months or longer after the second dose.

Boosters helped restore some of that immunity, but their advantages have faded as well. Booster shots were around 40% to 50% good at stopping Omicron infections and 75 percent to 85 percent effective at preventing hospital admissions for all adults 4 to 6 months after a third dose.

In the United Kingdom, over two-thirds of the elderly have had a second, third, or fourth dose of the COVID-19 vaccine in the last five months, but only approximately half of the elderly in the United States have received their second or third vaccine dose in the last five months.

When comparing antibodies’ protection from a previous COVID-19 infection, the United Kingdom once again comes out on top. As per the Office of National Statistics, 98 percent of adults in the UK have tested positive for antibody to COVID-19 by the end of February. In the United States, the CDC reports that 43% of individuals have antibodies to COVID-19 from a prior infection. Seniors, on the other hand, are significantly less likely to be protected, with only 23% of adults over 65 testing high for antibodies from a past illness.

Kissler tells CNN that he still thinks it’s a cause for concern that one may still witness a higher fatality rate and more hospitalizations for COVID in the United States than in the United Kingdom due to differences in underlying immunity. While a BA.2 wave in the United States may not be as extreme as it is in Hong Kong, it may not be the same experience as it is in the United Kingdom.

What is seen in the UK is likely going to be a better narrative than what can be expected in the US, Keri Althoff, an epidemiologist at Johns Hopkins Bloomberg School of Public Health, opines. With only a few weeks to prep, Kissler and Shaman suggest starting with immunizations and boosters for seniors.

Every incremental layer of defence that one gets helps, Kissler says. He would definitely advocate being vaccinated, especially if one is elderly and has not done so yet, because it really can go a long way towards providing people with the lasting and robust immunity that they desire, and that is why this is, without a shred of doubt, the right time.