Things you should know about Oxford's Covid-19 vaccine

A mass-vaccination drive is underway in Bangladesh, with an aim to inoculate some 35 lakh people in the first phase with the Oxford-AzstraZeneca vaccine.

In such a circumstance, the WHO Strategic Advisory Group of Experts on Immunization (SAGE) has issued interim recommendations for use of the Oxford-AstraZeneca Covid-19 vaccine. 

Who should be vaccinated first?

While vaccine supplies are limited, it is recommended that priority be given to health workers at high risk of exposure and older people, including those aged 65 or older.

Countries can refer to the WHO Prioritization Roadmap and the WHO Values Framework as guidance for their prioritization of target groups.

Who else can take the vaccine?

Vaccination is recommended for persons with comorbidities that have been identified as increasing the risk of severe Covid-19, including obesity, cardiovascular disease, respiratory disease and diabetes. 

Although further studies are required for persons living with HIV or auto-immune conditions or who are immunocompromised, people in this category who are part of a group recommended for vaccination may be vaccinated after receiving information and counselling. 

Vaccination can be offered to people who have had Covid-19 in the past. But individuals may wish to defer their own Covid-19 vaccination for up to six months from the time of SARS-CoV-2 infection, to allow others who may need the vaccine more urgently to go first.

Vaccination can be offered to breastfeeding women if they are part of a group prioritized for vaccination. WHO does not recommend discontinuation of breastfeeding after vaccination. 

Should pregnant women be vaccinated?

While pregnancy puts women at higher risk of severe Covid-19, very little data are available to assess vaccine safety in pregnancy. 

Pregnant women may receive the vaccine if the benefit of vaccinating a pregnant woman outweighs the potential vaccine risks. 

For this reason, pregnant women at high risk of exposure to SARS-CoV-2 (e.g. health workers) or who have comorbidities which add to their risk of severe disease, may be vaccinated in consultation with their health care provider.

Who is the vaccine not recommended for?

People with a history of severe allergic reaction to any component of the vaccine should not take it.

The vaccine is not recommended for persons younger than 18 years of age pending the results of further studies.

What's the recommended dosage?

The recommended dosage is two doses given intramuscularly (0.5ml each) with an interval of 8 to 12 weeks. 

Additional research is needed to understand longer-term potential protection after a single dose.  

Is it safe?

While this vaccine has yet to be recommended for an Emergency Use Listing by WHO, it has undergone review by the European Medicines Agency (EMA) and consequently meets WHO's criteria for SAGE consideration.

The EMA has thoroughly assessed the data on the quality, safety and efficacy of the vaccine and has recommended granting a conditional marketing authorisation for people aged 18 and above. 

The Global Advisory Committee on Vaccine Safety, a group of experts that provides independent and authoritative guidance to the WHO on the topic of safe vaccine use, receives and assesses reports of suspected safety events of potentially international impact. 

How efficacious is the vaccine?

The AZD1222 vaccine against Covid-19 has an efficacy of 63.09% against symptomatic SARS-CoV-2 infection.

Longer dose intervals within the 8 to 12 weeks range are associated with greater vaccine efficacy.

Does it work against new variants?

SAGE has reviewed all available data on the performance of the vaccine in the settings of variants of concern. SAGE currently recommends the use of AZD1222 vaccine according to the WHO Prioritization Roadmap, even if virus variants are present in a country. Countries should assess the risks and benefits taking into consideration their epidemiological situation.

Preliminary findings highlight the urgent need for a coordinated approach for surveillance and evaluation of variants and their potential impact on vaccine effectiveness. As new data become available, WHO will update recommendations accordingly. 

Does it prevent infection and transmission?

No substantive data are available related to impact of AZD1222 on transmission or viral shedding.

In the meantime, we must maintain and strengthen public health measures that work: masking, physical distancing, handwashing, respiratory and cough hygiene, avoiding crowds, and ensuring good ventilation.