Around 60 percent effectiveness, do vaccines AstraZeneca and Janssen work well enough?

Many vaccine news today: not only has the Astrazeneca vaccine been approved as a third vaccine against the coronavirus, but also more information came out about the Janssen vaccine. That hasnt been approved yet. Of both vaccines it is noticeable that the effectiveness is lower than the previously authorised vaccines: according to major studies, AstraZeneca has an effectiveness of 60 percent, Janssen claims a protection of 66 percent. At Pfizer and Moderna, its over 90 percent. The figures raise the question: are the new vaccines effective enough?

On social media, a number of people respond skeptically to the relatively low effectiveness. Also, there are people who are wondering why they are not allowed to choose which vaccine to get.

According to several experts, the lower effectiveness does not matter much. โ€œAn effectiveness of around 60 percent means that around 60 percent of the disease can be prevented. Thats quite a sip on a drink,โ€ says immunologist Cรฉcile van Els.

Epidemiologists Alma Tostmann and Frits Rosendaal and vaccinologist Ben van der Zeijst also find news about the Astrazeneca and Janssen vaccines good news, even though they are less effective than those of Pfizer and Moderna. โ€œThese vaccines may seem second choice, but in both, the full story is important. For example, AstraZeneca protects 85 to 100 percent against serious illness caused by covid-19, says Van der Zeijst.

Janssen also protects 85 percent against serious illness and 100 percent from hospitalizations – according to the companys preliminary data. This is achieved after one prick, unlike the other vaccines; two pricks are needed. โ€œThis is much more convenient and faster and that percentage will probably not reach Pfizer and Moderna after one shot,โ€ says Rosendaal.

Great Effect

The vaccines are going to have a major effect on the epidemic, says Rosendaal. โ€œIn the end, you want to get down the now known R-number.โ€ Thats the reproduction number of the virus, which indicates how quickly it spreads. Meanwhile, the basal R number of corona is estimated to be around 2: that means that one person infects two people. By all corona measures, the effective R was estimated at 0.93 on January 8. โ€œA measure such as a curfew is expected to decrease the R number by 0.13, which is much and much lower than what these vaccines can achieve.โ€

You can look at two things about the effectiveness of a vaccine: the efficacy at the individual level and the effectiveness on group immunity. โ€œOn an individual level, 60 or 66 percent effectiveness is obviously less good: everyone now wants to have their grandmother vaccinated and protect 100 percent. But I prefer to look at the big picture and that is positive,โ€ says Tostmann. โ€œIf about 60 percent across the country is immune to the coronavirus, you wont have any major outbreaks. Perhaps small outbursts, but you have protected enough people to prevent large-scale spread.โ€

In addition, its not just about effectiveness, immunogenicity says something, says immunologist Van Els. โ€œThat number shows if youre raising immunity with a vaccine. If that happens, the vaccine will be activated and your defenses will respond. This way you train your immunity and your body repels faster when infected with the coronavirus.โ€

Neutralising antibodies were found in 99 percent of subjects vaccinated with the Astrazeneca vaccine. In the case of the Janssen vaccine, provisional data also indicate a high percentage of antibodies that developed: between 82 and 94 percent. โ€œThats good news. Your immune system is then 1-0.โ€

Also, the spread of the virus is lower in the Astrazeneca vaccine. Tostmann: โ€œIf a vaccine works very well against transmission, thats a big plus too.โ€

Other vaccines for the elderly?

With the Astrazeneca vaccine, there are also concerns on social media about the small amount of data available on protection for people over 55. According to the experts, these concerns are not necessary. โ€œIt would be strange if a vaccine works up to 55 years and then after 55 years suddenly no longer. There are no indications for that,โ€ says Frits Rosendaal. โ€œThe reason that there is no data is because too few people over 55 were involved in the investigation. Not with the vaccine.โ€

However, the lack of data may be a reason for adjusting the vaccination strategy and giving elderly people another vaccine, which has been proven to be effective. โ€œMaybe you should choose Pfizer or Moderna in the elderly,โ€ says Rosendaal.

Van der Zeijst also thinks that the vulnerable groups should not be able to get the vaccines from Janssen or AstraZeneca, if that is the choice. โ€œBut probably the people over 65 wont even get these vaccines, because in the Netherlands we only want to use rna vaccines in the elderly.โ€ Thevaccines from AstraZeneca and Janssen are based on so-called vector technology.

What the difference is and how the vaccines can protect you later, you can see in the video:

According to Tostmann, it is a good idea to use the lower effectiveness vaccines to prevent the spread of the virus, and to use the higher effectiveness vaccines for individual protection. โ€œBut you want to protect the vulnerable as soon as possible.โ€

Actually, Rosendaal says were making things far too complicated. โ€œThe most important thing is that we vaccinate as many people as possible as soon as possible.โ€

Immunologist Van Els also says that the focus should be on the speed of vaccination. โ€œIm an optimist, so thats gonna be okay. But Im also a realist. And that means that I see that we are in a pandemic and that every effective vaccine is welcome.โ€