Although there are now millions of vaccinated people, we still don’t know how much the virus is replicating in them or if it is low enough to prevent spread to other people.
Experts are also expressing some concern about vaccine resistance or vaccine escape. This is a very rare case when a variant of the pathogen is unaffected by the vaccine and then can infect and cause illness in the person.
Most evidence suggests that may not be happening yet, although some data from South Africa suggests that the AstraZeneca/Oxford vaccine is less effective against the variant there. “At the moment, it is very difficult to examine lab data and predict what will happen in humans,” writes viral immunologist Sarah L. Caddy in The Conversation. “First, we don’t know the minimum number or ‘titre’ of effective antibodies needed to protect someone from the virus.”
The story of one patient may help scientists better understand what the virus does in our bodies and how it’s mutating. A 45-year-old man had an infection that lasted five months in 2020. Unlike others who may pass the virus and have lingering symptoms, this patient had active virus in his body for that entire period of time, reports NPR.
Scientists can look at samples taken periodically from the patient and compare them. If the virus was mutating in the patient’s body, then they should be able to see it.
And in this case, they did. “I was shocked,” says Jonathan Li at Harvard Medical School, according to NPR. “When I saw the virus sequences, I knew that we were dealing with something completely different and potentially very important.”
The patient had a compromised immune system, which experts think is why the virus persisted. A paper in the New England Journal of Medicine chronicles their illness and the analyses that resulted from the study of their samples. The length of time that the virus was able to survive in the patient’s body may have been a factor that allowed it to mutate as much as it did.
However, mutations don’t always lead anywhere. It’s a normal process that all viruses go through without intention. So more mutations does not necessarily mean a deadlier, more transmissible or significantly different virus will surface. And that could be good for vaccines. “On a more reassuring note, scientists widely agree that it is very unlikely a few virus mutations will render the current COVID vaccines useless,” writes Caddy. “However, mutations may make these vaccines less effective overall.”
Experts are hopeful that vaccines can be adapted to help deal with the variants, especially with messenger RNA (mRNA) vaccines which can be easily tweaked and updated. Research groups and vaccine developers are already working on this problem, but it may take time to get the new versions out.
For up-to-date information about COVID-19, check the websites of the Centers for Disease Control and Prevention and the World Health Organization. For updated global case counts, check this page maintained by Johns Hopkins University or the COVID Tracking Project.
You can follow Chia-Yi Hou on Twitter.
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