EEH: Variants vs. vaccines – Who will win the race?

One year after the spring 2020 COVID-19 wave came through the community leading to the first surge of COVID-19 hospitalizations, there is another potential wave of COVID-19 hospitalizations.

Each time SARS-CoV2 (the virus that causes COVID-19) replicates, it can mutate. With the rapid pace of viral spread worldwide, the many opportunities to mutate has led to a natural selection for variants that are more fit, that can out-compete and become dominant.

At the same time, three highly effective COVID-19 vaccines are now available and are slowly but steadily protecting the population.

It’s a race between the variants and the vaccine.

Early in the pandemic, the D614G variant emerged and quickly became the dominant strain by March 2020. In November 2020, England reported the B.117 variant. This variant has several mutations on the spike protein, most notably the N501Y mutation, which is thought to allow better attachment to the ACE-2 receptor.

In South Africa the B.1.351 variant, and in South America the P.1 variant, also carry the N501Y mutation as well as the E484K mutation, which make it less able for antibodies to attach to and neutralize the virus. In California the B.1427 and B.1429 variants have emerged and may also be more transmissible.

Antibodies generated from COVID-19 immunizations neutralize the B.117 variant nearly as well as the D614G variant, but not as well against the B.1.351 and P.1 variants. The Moderna and Pfizer-BioNTech vaccines were found to be 94-95% efficacious in preventing symptomatic infection and 95-100% against severe infection, but were not trialed at a time or in countries with circulating variants.

Antibodies from people who received Moderna or Pfizer vaccines were still able to neutralize the B.1.351 and P.1 variants, though at a diminished level. The Janssen (Johnson & Johnson) vaccine was trialed in South Africa (where the B.1.351 variant predominates), and though it was found to have a lower efficacy compared to the U.S., it was still highly effective in preventing severe infection, with no hospitalizations or COVID-19 deaths in vaccine participants.

While the efficacy of the three COVID-19 vaccines has been proven across adults of all age groups and medical conditions, experts still don’t know the level of protection for those who are immunosuppressed.

In the U.S., the variants that are less responsive to vaccines are rare: the B.1.351 variant accounted for 0.3% of cases and the P.1 variant 0.1% of cases through March 13. However, the more transmissible B.117 variant is slowly becoming more prevalent in the U.S., rising from 0.5% of cases in January to 9.5% by March 13. The more prevalent it becomes, the greater potential it has to spread more quickly, accelerating another surge. This threat can be stalled by getting more people vaccinated more quickly. It is literally a race between the vaccine and the variants.

The spring 2021 wave is unique in that it is affecting a new vulnerable population — those who haven’t been immunized. The spring wave of hospitalization is predominantly middle-age and younger adults, who have not yet had their turn to be vaccinated.

As of March 28, 2021, 28.2% of the U.S. population had received at least one dose of a COVID-19 vaccine and 15.5% have been fully vaccinated. Soon everyone age 16 and older will have the chance to be vaccinated.

Now is the time for unvaccinated people to diligently avoid getting infected until they are fully immunized. Immunity from vaccines allows people to clear the virus quickly if infected and protects them from severe infection, while masks, social distancing and hand washing help prevent infection.

For more information, visit www.eehealth.org/coronavirus.