Astra Zeneca's Phase 1 study in humans included just over a thousand people, half of whom received the experimental vaccine and the other half as a control group. Only ten people received two doses of the vaccine. According to the study, the subjects developed antibodies against the coronavirus, but the level was low, says Gunilla Karlsson Hedestam.

- Among the ten subjects who received two doses, the antibody level went up but the response was still modest and probably not enough to block the infection.

An effective vaccine must stimulate antibodies that neutralize the virus and protect against infection in order to limit its spread.

Short-term immunity

The researchers who developed the vaccine themselves say that it is too early to determine whether the vaccine provides sufficient protection against the infection and Gunilla Karlsson Hedestam is skeptical. Another question is how long the vaccine protects.

- With these low levels, immunity will fade faster than if higher levels are reached.

- This is not a miracle, but no one yet knows how strong an immune response is needed. We have to wait for the phase 3 results, says Gunilla Karlsson Hedestam.

protein Based

Astra Zeneca's experimental vaccine is based on an experimental gene technology, in which a sars cov-2 gene is added and it is expected that the body's own cells will produce the viral protein, which the immune system will then respond to. Gunilla Karlsson Hedestam believes that this type of technology provides a relatively small vaccine dose and believes that there will be other more promising vaccine candidates.