COVID-19 third wave experience in India, a survey of 5971 adults

Background

The third wave of the pandemic in India lasted from January till March 2022, and breakthrough infections were common. Third dose of vaccine was rolled out to priority groups in the beginning of 2022. There is no published information available about the clinical outcomes in this context.

Aims

• To assess the community level experience of the pandemic, with focus on the third wave and vaccination in India.

• To describe the experience of the boosted and non-boosted population during the 3 ^rd wave.

• To study the public perception about the precautionary (3 ^rd ) dose in India.

Results

Among 5971 respondents, 98.6% were vaccinated, 40% of whom had also received the 3 ^rd dose. Age range: 24% were below 40, 50% were 40-59, 26% were >60 years.

45% were women, 53% were healthcare workers.

COVID-19 was reported by 3361 (56%) respondents. Among those who reported COVID-19, 2311 (70%) were infected during the third wave. Severe symptoms occurred in <1%, while moderate severity was reported by 42%. Repeated bouts of infection were common; 15% of those with a history of COVID-19 had been infected at least twice. 44% of the respondents (2610/5971) did not report a history of COVID-19.

The third dose was taken by 2383 individuals, of whom 30% reported COVID-19 during the 3 ^rd wave. The boosted group also had higher N95 use, and a greater proportion of healthcare workers. Among those who did not take a 3 ^rd dose, 45% reported COVID-19 in the 3 ^rd wave. COVID-19 incidence was lower at 27% among those in this group who had recently received their second dose. Longer gap after the second dose correlated with higher chance of infection during 3 ^rd wave. Giving a 3 ^rd dose before a 6-month gap since the second dose did not make a difference in infection rate.

Covaxin and Covishield recipients had the same incidence of COVID-19 during the third wave.

While 35% of the respondents believed it was helpful, 65% of the respondents were either uncertain or disapproving of the benefit of a 3 ^rd dose.

Conclusions

• 30% of respondents who received a 3 ^rd dose went on to get COVID-19 during the 3 ^rd wave.

• Younger adults were more likely to be affected during 3 ^rd wave.

• Although severe disease was rare, 42% reported having symptoms of moderate severity that could temporarily incapacitate people, affecting their routine and productivity.

• The proportion of different grades of severity was similar among all vaccinated people, regardless of whether they received a 3 ^rd dose.

• Reinfections occurred in 15%, and were not always milder.

• Among those who did not receive a 3 ^rd dose, 45% reported COVID-19 in the 3 ^rd wave. However, this group had lower use of N95 masks (50%) than the 3 ^rd dose group (68%) which may have reduced the overall protection.

• The longer the gap after the second dose, the greater was the chance of reporting COVID-19.

• People who received their second dose recently had the same incidence of third wave COVID-19 as following a 3 ^rd dose.

• The 3 ^rd dose, given too close to the second dose, made no difference in the infection rate.

• Covaxin and Covishield recipients had the same rate of COVID-19 in the third wave.

• Although the respondents were 98.6% vaccinated at baseline, there was considerable uncertainty (65%) amongst them about the benefit of a 3 ^rd dose.