A growing, nationwide problem of booster lag

The third dose is important because immunity from the two doses wanes after a while.

It has been nearly two months since the government allowed all adults to take a booster jab of a Covid-19 vaccine and people are not exactly queuing up in large numbers for their third shot. The third dose is important because immunity from the two doses wanes after a while. A district-level analysis shows this problem is widespread and worsening over time. Solving this problem might require efforts in more than one direction.

(HT Photos)

Even with a two-week delay, the booster

Share of people who are late on boosters by two weeks (%)

Delayed boosters are a nationwide problem

Apart from worsening over time, people missing their boosters is also a pan-India problem. By May 30, in half the districts of the country, 80% or more of those eligible had not taken their booster dose. In a full three-fourths of the districts, this share was above 72%. And in 90% of the districts, the proportion was above 66%.

Share of people who have missed boosters in districts (%)

Is the difference in booster coverage because of low or high base?

While most districts are doing badly on this count, are some doing relatively better just because they have a low share of eligible adults? For example, districts in Gujarat, Uttar Pradesh, Bihar, West Bengal, Odisha and Andhra Pradesh are performing relatively better. They were performing relatively worse in second-dose coverage nine months ago.

However, this is not the case when one looks at the entire country. The correlation between the share of adults eligible for boosters and the booster coverage is weak at the national level. For example, only 10.9% of Tamil Nadu was fully vaccinated nine months ago. Yet, 83.4% of the eligible people in the state have missed their booster shot. Punjab, parts of Maharashtra and Madhya Pradesh are in a similar category.

3rd dose coverage of eligible and share of adults eligible for 3rd dose on May 30

Are free vaccines making people turn up for boosters?

Given that large parts of the country are poor, free vaccines ensure people do not bear economic pain to protect themselves against the pandemic. However, as far as uptake of boosters are concerned, it is difficult to say if just making vaccines free helps. For example, boosters are free in both Delhi and Haryana. Although they have a similar share of eligible population – 27% adults in Delhi and 23% in Haryana – 71% have missed boosters in Delhi, compared to 83% in Haryana.

Can increasing the number of vaccination sites help?

There were 192 districts with up to 40 sites per million adults in the week ending August 30 last year (nine months ago) and 436 that had more than 40 sites per million. In the week ending May 30, districts in these categories were 303 and 325.

It is possible that increasing the number of sites will help. Consider Haryana, which is performing poorly on booster coverage. Ten of its 21 districts are in the under-40 sites per million adults category now compared to four earlier. On the other hand, 10 districts in Bihar and seven in Odisha, states performing relatively better, had only up to 20 sites per million population nine months ago. Such districts now number slightly less there – six and four, respectively.

None of the interventions may work in isolation, but it should be expected that states that make vaccines both free and accessible will surge ahead in terms of administering booster shots.

Average vaccination sites in week ending August 30, 2021 and May 30, 2022 (per million adults)