Why reinfections are making search for vaccine hard

John Kinyanjui had just celebrated what he thought was his recovery from Covid-19. He tested positive for the coronavirus in May after being admitted to hospital suffering from shortness of breath, blocked nose and fever. By mid-June, the symptoms had subsided and he was feeling better.

“From what I had read and had been told by the doctor who attended to me, I had developed some form of immunity and I would not have to worry about coronavirus for a long time,” he says.

In the first week of July, he woke up with joint pains and shivers. The next day, he had lost his sense of smell. The feeling as if something heavy had been placed on his chest was familiar. He went back to hospital and re-tested positive for coronavirus.

“It is depressing, knowing that the symptoms will keep coming,” he says.

What was even more confounding, he adds, was that his symptoms were more intense than before. He is yet to regain his sense of smell.

His case is not unique. Globally, medics are now warning that patients who have recovered from coronavirus are not as safe as previously reported. There are doctors who are recording that patients with re-infection seem to have more serious symptoms.

Earlier research had indicated that survivors of the disease developed functional, virus-neutralising antibodies that made them immune to the coronavirus. Anecdotal reports and research studies show cases of reinfection and returning symptoms a few weeks after the first infection.

Herd immunity

This further complicates the search for a vaccine as it means the researchers will have to come up with a safe and more potent vaccine that will be durable and effectively promote the production of antibodies. It also edges out herd immunity suggested by a section of scientists as a way of containing the disease.

“Antibody levels reducing over time is normal, but it typically happens more slowly. Antibody responses against the mumps, measles, and chickenpox viruses last for more than 50 years,” reads a report from King’s College, London.

Since the immunity is short-lived, herd immunity might not work due to the unending reinfections. Herd immunity is only effective with high percentage of people getting immune so that the chain of transmission is stopped. Reinfection rules out this.

Dr Matilu Mwau, the director general at Kemri, says researchers have been thinking the disease cannot relapse, but current literature shows it is not the case.

“This is a new disease and more research is being done every day to guide the process of finding a solution,” he said.

Dr Kuirithia Fredrick, a public health expert, says what is being witnessed in Kenya could either be a relapse of the disease or reinfection.

“What researchers are still struggling to understand is the body’s ability to produce immunity, how long the immunity is expected to last, and the number of antibodies that patients need to develop to become immune,” he says.

Everybody seems to react differently to the virus, making it even more complex to find a uniform way to manage it.

Other medics suggest that what is being referred to as reinfection could be “long haulers” who tend to carry the symptoms longer than the average person.

Galgallo Bocha, who recently got discharged from Coast General Hospital after a 35-day stay says he might be among those whose bodies carried the virus longer than the average person. Symptoms started with a fever and blocked nose in mid-June. By the time he was being admitted, he had developed sores in the mouth and could barely eat.

“The symptoms started, disappeared, and then became more serious. I had to be hospitalised for 35 days and it was quite scary,” he says.
He has since been discharged and says the experience has given him the drive to talk about his long journey to recovery and the stigma the coronavirus patients face.

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