Washington : More harmful viruses can evolve from the use of so-called “leaky” vaccines, researchers, including one of Indian-origin, have confirmed for the first time, reports PTI. Scientific experiments with the herpesvirus such as the one that causes Marek’s disease in poultry have confirmed the highly controversial theory that some vaccines could allow more-virulent versions of a virus to survive, putting unvaccinated individuals at greater risk of severe illness.
“The challenge for the future is to identify other vaccines that also might allow more-virulent versions of a virus to survive and possibly to become even more harmful,” said Andrew Read, an author of the paper. “When a vaccine works perfectly, as do the childhood vaccines for smallpox, polio, mumps, rubella, and measles, it prevents vaccinated individuals from being sickened by the disease, and it also prevents them from transmitting the virus to others,” Read said.
