Written By: Longjam Dineshwori | Updated : July 27, 2021 1:42 PM IST
Older people appear to have fewer antibodies against SARS-CoV-2.
Older age appears to be a strong risk factor for COVID-19 severity and mortality. According to the US Centers for Disease Control and Prevention (CDC), older adults are more likely to get severely ill from COVID-19, requiring hospitalization, intensive care, and a ventilator to help them breathe. They are also at higher risk of death, if they get infected. As per CDC, over 80% of COVID-19 deaths occur in people over age 65, and more than 95% in people older than 45. Countries around the world have been vaccinating high-risk populations, including older people, against Covid-19 on priority basis. But they aren't entirely safe just because they're vaccinated; the people around them need to be vaccinated as well.
Moreover, a new study has suggested that older populations are potentially more susceptible to new coronavirus variants even if they are vaccinated, highlighting the importance of promoting and accelerating vaccination drive to protect them. The study results were published on Wednesday in the Journal of the American Medical Association.
The laboratory study from Oregon Health & Science University stated that older people appear to have fewer antibodies against SARS-CoV-2, the virus that causes Covid-19. Antibodies are blood proteins that are made by your body to attack foreign substances such as viruses and bacteria.
Older people also appear to be more susceptible to breakthrough infections. Even if they are vaccinated, older populations are potentially more susceptible to the new 'more transmissible' variants, than younger individuals, said study's senior author Fikadu Tafesse.
Tafesse an assistant professor of molecular microbiology and immunology in the OHSU School of Medicine and colleagues measured the immune response in the blood of 50 people two weeks after they received their second dose of the Pfizer COVID-19 vaccine. Their blood serum was exposed to the original "wild-type" SARS-CoV-2 virus and the P.1 variant (also known as gamma) that originated in Brazil.
They found that he youngest group -- all in their 20s -- had a nearly seven-fold increase in antibody response compared with the oldest group of people, who were between 70 and 82 years of age. The younger a participant, the more robust the antibody response, the researchers said.
Even though they detected diminished antibody response in older people, the researchers emphasized that the vaccine still appeared to be strong enough to prevent infection and severe illness in most people of all ages.
The vaccine induces stronger immune responses than natural infection in most older individuals, even if they are lower than their younger counterparts, said co-author Marcel Curlin, M.D., associate professor of medicine (infectious diseases) in the OHSU School of Medicine.
Vaccinating the high-risk populations may make the difference between serious and mild disease and reduce the chances of transmitting the virus to another person, he added.
Vaccinations can reduce the spread of the virus, including new and potentially more transmissible variants. "The more people get vaccinated, the less the virus circulates," Tafesse said, as quoted by the Science Daily.
But vaccinated older people aren't entirely safe, if the people around them are not vaccinated. "Everybody needs to be vaccinated to protect the community," the study noted.
Citing low vaccination rate across United States, the researchers underscored the importance of promoting vaccinations in local communities, and inoculating older people as well as others who may be more vulnerable to COVID-19.
