As BA.5 cases rise in NC, Duke vaccine researcher sees reason for optimism

Yet again, a new COVID-19 variant is grabbing our attention.

As the COVID-19 pandemic continues to spawn new variants with improved ability to spread — even among people who are vaccinated and boosted — it is natural to question whether vaccines, all of which are based on the initial Wuhan-1 strain of the virus, are still working and worth getting.

It is also natural to feel increasingly vulnerable to infection, and wonder whether it’s time to go back to social distancing, masking and other measures that became so familiar to us not that long ago. Indeed, it is increasingly common for people to know a family member, friend, classmate or co-worker who was vaccinated and boosted but still got COVID.

But don’t panic.

There have always been vaccine breakthrough infections, even early in this pandemic when the dominant variant was less mutated and more closely matched to the vaccine.

New mutations have made the virus less susceptible to the antibodies that serve as a first line of immune defense against infection. People who are vaccinated but not boosted have very low levels of protective antibodies against the BA.1 and BA.5 variants. A boost dramatically increases these levels, but the antibodies are three to four times less effective against BA.1 and about 10 times less effective against BA.5 compared to the original Wuhan-1 strain.

And by partially escaping this first line of immune defense, the virus can keep spreading from person to person, thereby assuring its survival in the human population.

However, soon after the virus penetrates this initial barrier and begins replicating in the body, it encounters a second line of immune defense that is more effective than antibodies alone. This second line of defense cuts the infection time short, decreases the chances of severe disease and death, and makes it less likely the virus will have adequate time to spread to another person. Fortunately, for people who are vaccinated and boosted, this second line of defense appears to be holding up quite well against all variants including BA.5, the newest one you’re now reading about in the news.

The FDA has recommended vaccine manufacturers develop a new booster for the fall attacking the BA.5 variant. This will tighten up that first line of defense – as well as the second.

In North Carolina and beyond, COVID-19 is likely to be with us indefinitely. It will periodically produce new variants and associated waves of infections, hospitalizations and deaths. But as more and more people acquire some level of immunity, either through vaccination, infection or both, and especially as more people get recommended booster shots, future waves should be less severe and less likely to spawn new variants so quickly.

We have also seen early evidence of how the vaccines can be modified periodically as needed to keep pace with the continued evolution of the virus, much as they are for flu. Although additional time is needed to better understand the evolutionary potential of the virus and the long-term benefits of vaccines, there is reason for optimism that the COVID-19 pandemic is winding down, even as we see BA.5 taking over as the major variant.

That said, as long as COVID-19 is with us, elderly people and those with underlying medical conditions who have weakened immune systems should take extra precautions, even if fully vaccinated and boosted, because their immunity may not be as strong or long lasting.

This story was originally published July 14, 2022 at 11:41 AM with the headline "As BA.5 cases rise in NC, Duke vaccine researcher sees reason for optimism."