Two vaccines typically given in childhood may strengthen the body’s protection from severe COVID-19 infection, says a new study.
The Measles-Mumps-Rubella (MMR) vaccine, which is administered during early childhood, and the Tetanus-Diphtheria-Pertussis (Tdap) vaccine, which is administered every ten years, may have an unexpected benefit: they may prevent severe covid-19, according to Harvard Medical School researchers.
The study results come at a time when the United States is seeing a fresh wave of coronavirus infections, which this time may have a considerably greater impact on children. The researchers speculated that these vaccines would generate cross-reactive memory T cells capable of responding to protein targets called antigens found in other pathogenic microorganisms, including the viral antigens seen in SARS-CoV-2.
Pre-existing memory T cells created by past MMR or Tdap vaccination and triggered by SARS-CoV-2 infection provide the immune system a head start in reacting, scientists reported in a study published in the peer-reviewed journal Med.
To determine whether the MMR and Tdap vaccines provide additional protection against covid-19, researchers at Brigham and Women’s Hospital affiliated with Harvard Medical School conducted laboratory-based analyses utilising sensitive, new techniques for detecting and characterizing T cell responses to antigens.
“Our Cleveland Clinic colleagues observed an association where individuals with covid-19 who had either MMR or Tdap vaccines had a much lower frequency of going to the intensive care unit or dying,” said co-author Andrew Lichtman.
“Although previous smaller studies suggested a similar link, our in-depth epidemiological analyses, together with our basic research results, suggest that these commonly given vaccines may protect against severe disease,” Lichtman added.
“During the covid-19 pandemic, we know that there was a marked decline in routine vaccinations for children and adolescents,” said corresponding author Tanya Mayadas.
“Our findings emphasize the importance of routine vaccination for children and adults. We know vaccines protect against devastating diseases, and we’re now seeing growing evidence that some of them provide a degree of protection against severe covid-19 disease.”
While the authors’ laboratory findings are supported by epidemiological studies, they note that additional work is needed to investigate the correlation between MMR and Tdap vaccinations and the severity of covid-19 disease in order to determine if the relationship is causal. Prospective research examining vaccination and patient outcomes may assist in differentiating correlation from causation.
“With regards to covid-19 vaccines, our findings predict that although MMR and Tdap are not a substitute for covid-19 vaccines they may afford greater and more durable protection, possibly against emerging spike variants than the covid-19 vaccine alone,” said Mayadas.
“And in areas where the covid-19 vaccines are not available, they could protect infected individuals from developing severe disease.”
The Harvard study is identical to one undertaken by BJ Medical College in India, which discovered that the measles vaccine had an 87.5 percent efficiency rate against the SARS-CoV-2 virus.
The study, which was published in the peer-reviewed journal Human Vaccines and Immunotherapeutics, also suggested that measles vaccination could provide long-term protection against covid infection in children.