The World Health Organization's recommendations for the use of the Oxford/AstraZeneca Covid-19 vaccine, AZD1222, include all people ages 18 and older, including older adults.

In a briefing on Wednesday, Dr. Joachim Hombach, executive secretary of WHO's Strategic Advisory Group of Experts (SAGE) on Immunization said:

“The immune response in people above 65 is almost the same as in younger people, and this makes us very confident.”

The new recommendations were published on Wednesday and note that there are some populations for which data are limited or do not exist — including children, pregnant women, lactating women and other groups. “Until such data are available, vaccination of individuals below 18 years of age is not recommended,” the guidance says.

“The available data on AZD1222 vaccination of pregnant women are insufficient to assess vaccine efficacy or vaccine-associated risks in pregnancy. However, it should be noted that AZD1222 is a nonreplicating vaccine,” it says. It added that “WHO does not recommend pregnancy testing prior to vaccination. WHO does not recommend delaying pregnancy because of vaccination.”

For women who are breastfeeding, the guidance says that “a lactating woman who is part of a group recommended for vaccination, e.g., health workers, should be offered vaccination on an equivalent basis.” It also said that it does not recommend discontinuing breastfeeding after vaccination

At the same briefing, WHO also recommended the Oxford/AstraZeneca vaccine in countries where variants of the coronavirus are circulating.

The group of expert advisers looked at two aspects of the circulation of the variants in relation to the AstraZeneca vaccine, said Dr Alejandro Cravioto, chair of WHO’s Strategic Advisory Group of Experts (SAGE) on Immunization.

In the United Kingdom, Cravioto said the preliminary analysis showed a slightly reduced efficacy against the variant first spotted there. The analysis also showed a limited reduction in titers of neutralization, which means the vaccine is still having a good effect on protecting people infected with that variant.

In South Africa, Cravioto said the preliminary analysis showed “a marked reduction” in vaccine effectiveness against mild or moderate disease in a variant first spotted there. The analysis also showed a reduction in neutralizing antibody levels. However, he said the study was small and didn’t allow assessment of the vaccine against severe infection. He noted there is indirect evidence that there is still protection against severe disease.