The Union health ministry, in its guidelines, has said that those who have recovered from Covid-19 should also get vaccinated. To those who are infected at the time of immunisation, the advisory has asked them to defer getting the shot by 14 days.
But considering those who have recovered from the disease would have developed a natural immunity to the coronavirus, is it sound to include them in the vaccination programme? Yes, say experts as there is still no clarity on how long the natural immunity lasts or how strong it is.
The current thinking is that antibody levels begin to drop after a few months -think asymptomatic and milder cases- eventually leaving people susceptible to catching the virus a second time (typically until three to four months after the first).
Though more research is needed, health experts suspect that people with a recent Covid-19 infection may be able to hold off a few months before getting the vaccine. Those who have been recovered from Covid for several months, however, should plan to get the shot as soon as it becomes available to them.
Onyema Ogbuagu, an infectious disease doctor at Yale Medicine who has been testing the Pfizer vaccine, told Huffpost he would recommend the vaccine for someone who had Covid three to four months ago (or longer), especially if it was a milder case. Evidence suggests that those who had a more serious go of it may emerge with more durable protection that could last for several months.
Researchers currently suspect that immunity conferred by the vaccine will be more robust than immunity achieved from natural disease. But the theory is still being tested. And regardless of whether you had a mild or severe case, you’ll want to get the shot at some point.
According to Ogbuaga, vaccine clinical trials only recently started focussing on participants who’d had Covid to learn more about the body’s response to vaccination where there had already been an immune response.
One theory is that the vaccine could increase antibody levels in people who’ve already been infected, essentially working like a booster shot. But there’s also a chance that vaccination on top of natural immunity could lead to a severe reaction in certain people.
Some doctors have also toyed with the idea of conducting antibody tests to determine if someone has natural immunity before administering the vaccine. In theory, testing for neutralising antibodies would identify people with no immunity who could be prioritised for vaccination so we can reach herd immunity faster. ( TOI )
