Why a New mRNA-Based Flu Vaccine May Be the Most Effective Yet

Why a New mRNA-Based Flu Vaccine May Be the Most Effective Yet

Moderna reported on July 7 2021 that participants received vaccination doses in the Phase 1/2 study of mRNA-1010, the company’s seasonal influenza mRNA vaccine for healthy adults in the United States.

This is the first seasonal influenza vaccine candidate to enter the clinic and targets lineages suggested by the World Health Organization to fight against corona.

The vaccination is to battle against influenza:
  • H1N1. 
  • H3N2
  • influenza B.
  • Yamagata
  • Victoria.
Moderna plans to enroll 180 participants in the study.

Why a New mRNA-Based Flu Vaccine May Be the Most Effective Yet

Moderna reported that they’ve started the human trials for a new mRNA flu shot. 
If effective, it may provide better protection than the previous vaccines and it also may be easier and faster to produce.
  • Moderna started human trials for a potential new influenza vaccine.
  • The new vaccine uses mRNA technology, it is the same technology used to create the Moderna and Pfizer COVID-19 vaccines.
  • If it succeeds the vaccine would be more effective than the current flu shot.
 Why change the flu vaccine?
The WHO assesses that 3 to 5 million instances of flu occur every year all around the world, causing 290,000 to 650,000 respiratory deaths and the CDC Centers for Disease Control and Prevention announced that the flu vaccine helps to reduce the risk of flu illness between 40 to 60 percent among the overall population during seasons when most circulating flu viruses are matched to the flu vaccine.

Moderna tries to improve the effectiveness of the vaccine by developing different antigen combinations against seasonal influenza viruses.

“We are living at a very exciting time in medicine, when DNA sequencing technology will allow us to identify genetic causes for many diseases and will expand our options for therapeutics,” Dr. Scott Braunstein

He adds that this technology has been studied since the 1980s while many people worry that it is new and untested.

 what is mRNA?
mRNA or Messenger RNA is a single-stranded RNA molecule that completes one of the DNA strands of a gene.
The mRNA is an RNA version of the gene that moves to the cytoplasm from the cell nucleus. During protein synthesis, the ribosome moves all along the mRNA, to read its base sequence, and uses the genetic code to translate each three-base, into its corresponding amino acid.

 Another explanation for the mARN:

Messenger RNAs, are one of the types of RNA that are found in the cell. The mARN is like most RNAs, it is made in the nucleus and then it moves to the cytoplasm where the translation machinery, the machinery that makes proteins, binds to these mRNA molecules and reads the code on the mRNA to make a protein. In general, one gene, can be transcribed into an mRNA molecule that will end up by making one specific protein.

What is an mRNA vaccine?

Braunstein explains that mRNA vaccines instruct our cells to produce just a piece of a protein and harmless protein . This shows to the immune system to neutralize pathogens carrying the proteins when a person becomes infected in the future.
He also said that Spike protein, carried by SARS-CoV-2, is an example, but other viruses, including influenza, also carry signature proteins on their surface.

Current flu shots contain inactivated versions of the influenza virus, which are cultivated in either eggs, or animals cells.

“This can take months to develop, and limits the speed with which vaccines can be produced. An mRNA-based flu shot can be produced much more quickly [as new flu strains arise,” said Braunstein.

He explained that because the current flu vaccines takes months to be developed, scientists are forced to make their “best guess” as to what the most common strains will be when they reach the United States.

The formulation of the current vaccine is decided 6 to 9 months before it is intended to be used.

“In many cases, we guess wrong, which has led to only a 10 to 50 percent efficacy in some seasons. If mRNA technology is used, we would be able to develop vaccines which contain the most common strains of the season with much more precision, which should make the vaccinations far more effective,” Braunstein said.

  •  mRNA technology may be used to create vaccines for multiple different pathogens in the future, which may reduce the number of total vaccines administered, explained Braunstein.
  • It is likely that this technology will be used to show to  our immune system how to fight other ailments, including cancer.  Bucher noted that one concern associated with mRNA vaccines is the degree of reactions that occur after getting the shot. 
  • The increase in the number of components may also increase the reactogenicity.
She explained that the mRNA flu vaccine will require multiple components for the four main flu antigens (two type A and two type B).
 Moderna says it hopes to create a combination vaccines that could fight against flu, COVID-19, and other respiratory infections with one shot. “Our vision is to develop an mRNA combination vaccine so that people can get one shot each fall for high efficacy protection against the most problematic respiratory viruses,” Stéphane Bancel, chief executive officer of Moderna
If flu vaccine using this technology safe and effective, it could make us more prepared for a potential pandemic flu in the future. It’s a fairly simple process to design a shot that could target a new influenza virus. “[mRNA] gives us a very strong platform for a rapid response,” Rosemary Rochford, an immunologist at the University of Colorado, told The Verge last fall.
 what's the difference between covid and flu:
How are COVID-19 and influenza viruses similar?

 COVID-19 and influenza viruses have a similar disease presentation:

  • They both cause respiratory disease, which presents as a wide range of illness from asymptomatic or mild through to severe disease and death.
  • Both viruses are transmitted by contact. As a result, the same public health measures, such as hand hygiene and good respiratory etiquette (coughing into your elbow or into a tissue and immediately disposing of the tissue), are important actions all can take to prevent infection. 

 Common symptoms that COVID-19 and flu share include:

  • Fever
  • Cough
  • Shortness of breath / difficulty breathing
  • Fatigue (tiredness)
  • Sore throat
  • Runny / stuffy nose
  • Muscle pain /body aches
  • Headache
  • Vomiting 
  •  diarrhea
  • Change in or loss of taste or smell
How are COVID-19 and influenza viruses different?
  • The speed of transmission: the speed of transmission is a very important point of difference between the COVID-19 and influenza . Influenza has a shorter median incubation period and a shorter serial interval than COVID-19 virus. The serial interval for COVID-19 virus is estimated to be 5-6 days, and the influenza virus is 3 days. 
  • The reproductive number: the number of secondary infections generated from one infected individual it is between 2 and 2.5 for COVID-19 virus, which is higher than for influenza. 
  • Children also are important drivers of influenza virus transmission in the community. For COVID-19 virus, initial data indicates that children are less affected than adults and that clinical attack rates in the 0-19 age group are low. Further preliminary data from household transmission studies in China suggest that children are infected from adults, rather than vice versa. 
  • The most at risk for influenza infection are children, pregnant women, elderly, those with underlying chronic medical conditions and those who are immuno suppressed. For COVID-19, our current understanding is that older age and underlying conditions increase the risk for severe infection. 
  • Mortality for COVID-19 appears higher than for influenza, especially seasonal influenza. While the true mortality of COVID-19 will take some time to fully understand, the data we have so far indicate that the crude mortality ratio is about 3%, the infection mortality rate will be lower. 

Which is More Dangerous: Flu or COVID-19? 

 it is clear that the flu is a lot less deadly than COVID, Dr. Olulade said. "We’ve definitely seen more deaths with COVID and the fact that we don’t have any FDA approved treatments for COVID, we don’t have a vaccine for COVID. It’s a really novel virus that really none of us have ever come in contact with and that’s extremely dangerous when it comes to COVID."