Investigation of the COVID-19 vaccine from Johnson & Johnson
The Johnson & Johnson COVID-19 vaccine is one of the four vaccines against COVID-19 so far approved by the European Medicines Agency (EMA).
On 9 April, the EMA fast-tracked an investigation of the link between the rare symptoms known as VITT (vaccine-induced immune thrombotic thrombocytopenia) and the vaccine from Johnson & Johnson after cases had been reported in the USA. In April, the EMA confirmed that there is a possible link between the Johnson & Johnson vaccine and the unusual VITT syndrome with a combination of blood clots in unusual sites, low levels of blood platelets and several cases of bleeding.
In this theme, you can read about the drug regulatory authorities’ investigations of the suspected side effects and the unusual VITT syndrome of the Johnson & Johnson COVID-19 vaccine. The vaccine has not yet been introduced in Denmark, and the Danish Health Authority has decided to continue the COVID-19 vaccine roll-out without the Johnson & Johnson vaccine. In Denmark, no side effects concerning the Johnson & Johnson COVID-19 vaccine have therefore been reported because the vaccine is not part of the Danish COVID-19 vaccine programme.
The Johnson & Johnson vaccine was granted a conditional authorisation in the EU in March 2021 by the European Medicines Agency (EMA) because its benefits of preventing death and other health-related COVID-19 consequences outweigh the possible risks in the form of known and possible side effects.
News from the Danish Medicines Agency
EMA: Possible link between the Johnson & Johnson vaccine and unusual symptoms
(21 April 2021)
European Commission authorises COVID-19 vaccine from Johnson & Johnson
(11 March 2021)
EMA recommends conditional authorisation of the COVID-19 vaccine from Johnson & Johnson
(11 March 2021, in Danish only)
Links
Danish Health Authority:
The Danish COVID-19 vaccine rollout continues without the COVID-19 vaccine from Johnson & Johnson
(3 May 2021)
Danish Health Authority:
The vaccine from Janssen (Johnson & Johnson) may cause rare but severe side effects
(21 April 2021)
Danish Health Authority:
The COVID-19 vaccine from Johnson & Johnson (in Danish only)
European Medicines Agency (EMA):
COVID-19 Vaccine Janssen
European Medicines Agency (EMA):
EMA finds possible link to very rare cases of unusual blood clots with low blood platelets
(20 April 2021)
Assessment of very rare cases of unusual blood clots with low platelets continues
(14 April 2021)
The Johnson & Johnson COVID-19 vaccine in general
How the Johnson & Johnson vaccine works
The COVID-19-vaccine from Johnson & Johnson consists of a so-called adenovirus. The adenovirus is an inactivated version of a cold virus in which parts of it have been modified to look like coronavirus but without causing the disease.
If a person is vaccinated with the vaccine, the immune system will react and produce antibodies, thus getting ready to defend itself against coronavirus. If, later on, the vaccinated person comes into contact with COVID-19 virus, the immune system will recognise the virus and be ready to defend the body against it.
The basis leading to a conditional authorisation
Vaccine efficacy
The aim of the trials was to study the occurrence of COVID-19 among the participants who were well before and during vaccination.
Efficacy was measured based on more than 44,000 trial subjects from 18 years of age who had no signs of a previous infection. The study showed that the vaccine had a 67% efficacy in COVID-19 prevention two weeks after vaccination for all age groups included in the study. The efficacy of 67% was recorded to be the same across gender, age and ethnicity.
Of the 19,630 trial subjects who received the vaccine, 11 developed COVID-19. In comparison, 348 of the 19,691 trial subjects receiving a placebo developed COVID-19.
Side effects of the vaccine
The most common side effects observed in the clinical trials of the COVID-19 vaccine from Johnson & Johnson are:
- Headache
- Tiredness
- Muscle ache
- Nausea
- Fever
These side effects were generally mild or moderate and improved or disappeared within a few days after vaccination. Such side effects are signs that you have received a vaccine jab, that the immune system is reacting, and that the vaccine works as intended.
The COVID-19 vaccine from Johnson & Johnson will continue to be monitored carefully and is subjected to several measures to catch and record side effects that are specific to COVID-19 vaccines. Even though a very large number of people have been given COVID-19 vaccines in connection with the trials, very rare side effects could still emerge later when the vaccine has been rolled out to several million people. And this is closely monitored by drug regulatory authorities around the world.
Read more about the Johnson & Johnson COVID-19 vaccine