Immunity

Scientists have uncovered details regarding an immune response to a virus present in all human tissues, that kicks in in the elderly and eliminates senescent, or aging, cells in the skin. Senescent cells are those that stop dividing but do not die, accumulating in the body over time, fuelling chronic inflammation and contributing to conditions such as cancer and degenerative disorders. Eliminating senescent cells from aging tissues has been found to restore tissue balance in mice, leading to an increased healthy lifespan. When a team of scientists, led by Massachusetts General Hospital (MGH), US, found that the number of senescent cells in samples from old individuals did not increase as the individuals got older, they realised that there is some mechanism kicking in to keep the aging in check. The scientists have described their findings in the journal Cell. Experiments have proved that in the elderly, certain immune cells called killer CD4+ T cells keep senescent cells from ...

People who are obese may be more susceptible to severe COVID-19 because of a poorer inflammatory immune response, according to a study. The research, published in the American Journal of Respiratory and Critical Care Medicine, found that following SARS-CoV-2 infection, cells in the lining of the lungs, nasal cells, and immune cells in the blood show a blunted inflammatory response in obese patients, producing suboptimal levels of molecules needed to fight the infection. While some people have very mild -- or even no -- symptoms due to COVID-19, others have much more severe symptoms, including acute respiratory distress syndrome requiring ventilator support. One of the major risk factors for severe COVID-19 is obesity, which is defined as a body mass index (BMI) of over 30, the researchers said. While this link has been shown in numerous epidemiological studies, until now, it has not been clear why obesity should increase an individual's risk of severe COVID-19. "During the pandemi

Boosters conferred an additional 6 months of protection

While hybrid immunity is behind India's low COVID-19 numbers, a large section of China's population may not have this protection provided by a combination of vaccination and prior infection, leading to spurt in cases there, experts say. The experts also questioned the efficacy of the vaccines available to the people in China. India has been witnessing lowest COVID-19 numbers since the beginning of the pandemic, while China has seen record numbers of the viral disease in recent days. In the last 24 hours, India reported a rise of 165 COVID-19 cases, while the count of active cases has declined to 4,345, according to the numbers shared by the Union government at 8 am on Tuesday. The daily number of cases in the country had peaked at 4,14,188 (over 4.1 lakh) on May 7, 2021. The following month, on June 10, 2021, the number of deaths increased at 6,148. On the other hand, China reported 19,903 infections in 24 hours, according to the World Health Organisation. The recent daily cases

Hybrid immunity has led to the steady decline of Covid in India but the virus is destined to stay long-term, becoming endemic rather than getting eliminated, say scientists as masks rapidly become a thing of yesterday and pandemic memories begin to fade. Though Covid deaths have virtually ceased and case numbers are sliding, it would be a mistake to drop caution, they said, pointing to the impact of long Covid and the need to continue testing. According to immunologist Satyajit Rath, the future trajectory of the Covid pandemic depends to a large extent on two questions will new variants with unexpected characteristics arise, and how long will vaccine or infection-triggered immune protection last. "While the outlook seems good, I think caution is advisable," Rath, professor emeritus at Indian Institute of Science Education and Research, Pune, told PTI. Earlier this week, on Tuesday, India recorded its lowest single-day rise of 625 fresh COVID-19 cases since April 9, 2020 and report

Pre-clinical trials show no evidence of side effects in the product, which is the ninth such to be developed from marine organisms by Kochi-based CMFRI

China's National Medical Products Administration approved CanSino's Ad5-nCoV for emergency use as a booster vaccine

Study shows booster jab is effective against several Sars-CoV-2 strains such as Alpha, Beta, Delta, Delta Plus and Omicron, and also increases memory B-cell response

circumstances have changed dramatically over the course of the pandemic, with the original SARS-CoV-2 virus superseded by far more infectious variants.

'Vaccine equity not possible if we include imported mRNA vaccines in our programme', said Arora

The UK rolled out fourth doses to over-75s and those over the age of 12 who are immunosuppressed in April. It is also offered in Israel and Germany

The DCGI has recently approved the emergency use of Covid-19 vaccine Corbevax for children aged five to 12. Find out more about the new vaccine and how it can boost the immune response

Asked about the dominant variant in the present surge, Dr Suresh Kumar said that the omicron sub-variant has been prevalent and ruled out the XE variant present in the incoming patients

Steady and stable infection rate with minor fluctuations for four weeks or more is when the disease is in endemic stage.

As much as 30 per cent individuals lose vaccine-acquired immunity after six months, according to a study conducted by AIG Hospitals along with the Asian Healthcare Foundation on Vaccine Immunity. The study was conducted on 1,636 healthcare workers who were fully vaccinated against COVID-19, a press release from AIG Hospitals said. "Our study results were at par with other global studies where we found that almost 30 per cent individuals had antibody levels below protective immunity level of 100 AU/ml after six months. These individuals were majorly above 40 years with co-morbidities like hypertension and diabetes. Out of the total, 6 per cent did not develop any immune protection at all," Dr D Nageshwar Reddy, Chairman, AIG Hospitals said. The results clearly indicated that with age, immunity waning is directly proportional which means that younger people have more sustained antibody levels than the elderly population. One of the most important results of the study showed that peop

The virus infects an individual in natural settings, and elicits three kinds of responses - antibody mediated, cell mediated immunity, and immunological memory, said ICMR Director General

But some virologists feel two-dose immunity, along with memory-cell action, may be sufficient

Now, subtle differences between the Pfizer Inc.-BioNTech SE and Moderna Inc. vaccines are emerging across patient groups over time.

From reactivation of herpes infection to loss of hair, several Covid patients in recovery phase are facing one dermatological complication or another due to lowered immunity, say doctors

Vaccination boosts the natural immunity so much that they are likely protected even from the emerging variants