Valneva: Inactivated vaccine against Corona

Valneva: Inactivated vaccine against Corona

Valneva’s dead vaccine, VLA2001, was the sixth corona vaccine to receive approval in Europe. Together with the Novavax vaccine, it offers an alternative to the previously approved mRNA and vector vaccines. What is known about the vaccine’s effectiveness, ingredients and side effects?

Corona vaccine from Valneva: This is how the inactivated vaccine works

Killed vaccines, also known as inactivated whole virus vaccines, contain killed pathogens (viruses) or their components, which can no longer multiply. The principle of the inactivated vaccine is already used for other vaccinations such as diphtheria, hepatitis B, Hib (Haemophilus influenzae type b), poliotetanus or whooping cough.

With VLA2001, cell cultures of the original coronavirus are multiplied in the laboratory (in so-called Vero cells) and then inactivated. The virus’s protein remains intact with this method, but the coronavirus itself cannot multiply or infect cells.

When vaccinated, the body recognizes the pathogens as foreign. The immune system responds and begins to produce antibodies and helper T cells. If a vaccinated person later comes into contact with SARS-CoV-2, the body recognizes the virus and immediately begins to fight it.


Ingredients of the Valneva vaccine

In addition to the killed coronaviruses, Valneva’s whole virus vaccine contains two adjuvants (vaccine boosters):

  • Aluminium hydroxide: The adjuvant is based on aluminium compounds and stimulates the vaccine’s immune response. For example, it is already being used successfully in vaccines against diphtheria and tetanus.
  • CpG 1018: This is a piece of DNA that is already used in a hepatitis B vaccine. CpG 1018 (cytosine phospho-guanine) mainly stimulates the immune response of the T cells. T cells recognize foreign bodies and sound the alarm. In addition, they recognize already infected cells and kill them.

Benefits of Valneva’s Inactivated Corona Vaccine

With the previous coronavirus vaccines, the focus is on the spike protein of the virus. This is responsible for docking the pathogen to human cells and has been used in previous coronavirus vaccines to identify the virus. During vaccination with mRNA and vector vaccines, the body reproduces a piece of the spike protein so that antibodies and helper cells are made against it. Novavax’s recombinant protein vaccine contains the artificially produced spike protein based on this part of the virus.

The advantage of Valneva’s inactivated vaccine is that it contains the entire virus, not just parts. The immune system can react to the entire virus and thus also develop an immune response, for example, against the virus envelope. The inactivated vaccine could be more effective with virus variants.

Another advantage lies in transporting and storing the inactivated vaccines – the vaccine can be stored at refrigerator temperatures for several years.


Valneva: Phase 3 study proves efficacy

Almost 3,000 subjects aged 30 and over participated in the phase 3 study of Valneva’s inactivated vaccine. The results were compared to AstraZeneca’s (Vaxzevria®) vaccine and showed high efficacy of the Valneva vaccine.

Compared to the vector vaccine, a higher average level of neutralizing antibodies against SARS-CoV-2 was detected in the participants after two vaccinations. In addition, the inactivated vaccine generates a high immune response of the T cells against the spike protein of the virus and two other virus proteins. Additional data also showed an equally high effectiveness in producing antibodies in people aged 18 to 29.

Both vaccines prevented severe coronavirus diseases.

According to the approval, the vaccine is currently not to be used as a booster. According to the manufacturer, a third dose of the vaccine should further increase its effectiveness. However, as a third vaccination in combination with other vaccines, the vaccine performed weaker than other vaccines, according to a British study.

Valneva: Does the vaccine against omicron work?

According to the European Medicines Agency assessment, more data is needed on the effectiveness compared to the currently dominant omicron variant.

According to the manufacturer, however, initial laboratory studies show that three doses of the inactivated vaccine also have a neutralizing effect against the omicron variant of SARS-CoV-2. In the laboratory experiment, all serum samples showed neutralizing antibodies against the original coronavirus and the delta variant, 87 per cent against the omicron variant. However, the effectiveness of Omikron is 16.7 times weaker than that of the wild type.

Possible side effects of VLA2001

Vaccination reactions were lower in the pivotal study than AstraZeneca’s comparator vaccine. The side effects were mild and went away independently after a few days. The most common reactions (occurring in more than 1 in 10 people) were:

  • local reactions at the injection site, such as pressure and pain
  • fatigue
  • headache
  • Muscle aches
  • nausea and vomiting

Slightly less frequently (less than 1 in 10 people), they experienced itching, swelling and redness of the skin at the injection site, pain in the mouth and throat or fever.

Less than 1 in 100 people experienced any of the following side effects:

  • swollen lymph nodes
  • dizziness or fainting
  • Sensory or sensory disturbances such as numbness or tingling
  • taste disorders
  • migraine
  • abdominal pain or diarrhoea
  • excessive sweating
  • rash
  • Muscle spasms, joint pain or pain in the extremities

Less than 1 in 1,000 people also developed sensitivity to light, thrombocytopenia (lack of blood platelets), hives or thrombophlebitis (inflammation of a superficial vein associated with a blood clot).

As with all vaccines, it cannot be ruled out that infrequent side effects will only be detected after the vaccine has been used for some time.

Vaccination is not recommended if you have a known allergy to the ingredients. According to the European Medicines Agency (EMA), there is not enough data on use in immunocompromised people. While efficacy may be affected, there are no specific safety concerns. There is also currently insufficient data on use in pregnant and breastfeeding women, which is why this decision should be made on a case-by-case basis together with the doctor treating you.


Approval of the Valneva vaccine against Corona

On June 23, 2022, the European Medicines Agency gave the green light for the inactivated vaccine in the EU, and the European Commission officially approved it the following day. The vaccine is intended to be used in people between 18 and 50. Two doses of vaccine are given into the upper arm muscle 28 days apart.

The European Commission had already signed a pre-purchase agreement for 60 million vaccine doses with the Franco-Austrian pharmaceutical company at an early stage. However, since the approval had been delayed, there had been open speculation about terminating the contract in May. The pharmaceutical company is already examining the effectiveness and tolerability of the vaccine in children and adolescents – an extension of the approval will then be examined in due course.


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