While researchers all over the world are toiling day and night to find a vaccine against COVID-19 and people are pinning their hopes on them, here come’s a disclaimer: Early vaccines may come with limitations on what they can deliver, says Professor Robin Shattock of the Imperial College London, who is leading the development of an experimental shot.
“Is that protection against infection?” Shattock said. “Is it protection against illness? Is it protection against severe disease? It’s quite possible a vaccine that only protects against severe disease would be very useful.”
As countries emerge warily from lockdowns, leaders are looking to a preventive shot as the route to return to pre-pandemic life. Fueled by billions of dollars in government investment, vaccines from little-known companies like China’s CanSino Biologics Inc. and giants like Pfizer Inc. and AstraZeneca Plc are in development, reported The Indian Express quoting Bloomberg.
One of the fastest-moving experimental shots has advanced into human trials. So far, it has shown an impact on severe disease — but less so on infection — in animals. According to experts, such a product would probably be widely used if approved, until a more effective version comes to market.
“Vaccines need to protect against disease, not necessarily infection,” said Dennis Burton, an immunologist and vaccine researcher at Scripps Research in La Jolla, California.
According to WHO, in their attempts to confront a rapidly growing threat, developers are turning to technologies that have never been used successfully in humans. More than 130 shots are in the works for COVID-19 prevention.
Michael Kinch, a drug development expert who is associate vice chancellor at Washington University in St. Louis warns that while such vaccines might have the potential to save lives, lockdown-weary nations are likely to get complacent once they are out.
“My guess would be that the day after someone gets immunized, they’re going to think, ‘I can go back to normal. Everything will be fine,’” he said. “They’re not going to necessarily realize that they might still be susceptible to infection.”
COVID-19 is already thought to be spread by people without symptoms, and a symptom-preventing vaccine may create even greater numbers of them.
Vaccines are among the most effective weapons against infectious disease, and prevent up to 3 million deaths a year, according to the World Health Organization. Yet few, if any, are 100% effective in all people who get them. For example, about 3% of people who get measles vaccine develop a mild form of the disease, and can spread it to others.
