September 19, 2022 | Posted in Technology
Flu vaccines have undergone many changes, with several notable advancements credited to various technological developments. These include non-egg-based technology, mRNA technology, Nanoparticles, and COBRAs, to name a few. These advances have improved flu vaccines by a wide margin.
The development of mRNA-based flu vaccines is based on the fact that messenger RNA can stimulate robust immune responses. Companies such as Moderna and Pfizer-BioNTech developed flu vaccines before the coronavirus pandemic. Scientists have developed ways to protect mRNA from degradation and enhance its entry into cells.
The first flu vaccines made using mRNA technology are available in the United States. The company has built a factory in Norwood, Mass., to manufacture high-volume batches for clinical trials. This facility is expected to help the company produce more effective and safer flu vaccines.
The mRNA technology has also enabled researchers to include more than one antigen in flu vaccines. A study in 2020, for instance, tested vaccines containing four influenza proteins. It included a special hemagglutinin that had a stalk to direct an immune response away from the head of the virus. It also contained a viral protein called neuraminidase, which tends to be more conserved. Using multiple targets in a vaccine offers broader protection and hedges bets.
Cell-based technology has made influenza vaccine production much faster and easier. This method uses mammalian cells to grow influenza viruses to produce a more effective vaccine. This method also avoids the problems associated with egg-based production, like the virus adapting to the host, which can result in an ineffective vaccine. In addition, this method produces a virus more similar to the circulating strain of the disease.
Current flu vaccines are strain-specific and must be updated annually. This process includes screening different virus isolates for antigenicity and preparing reassortant viruses. This process can take 68 months, and there are many potential delays due to unexpected circumstances, such as low yields of virus samples. During this time, circulating influenza viruses have had ample time to mutate. A late-emerging variant of the H3N2 virus rendered the vaccine strain recommended for use in the previous season useless.
Adaptation in influenza viruses can occur at the same site as the dominant antigen, which makes egg-based vaccines less effective. Transformation can also occur in regions of the influenza virus that aren’t present in circulating viruses, and this can cause the antigens to be different. As a result, HA is an essential target for neutralizing antibodies. HA facilitates the entry of influenza viruses into host cells by binding to the sialic acid on the cell’s surface. Human influenza HA prefers a-2,6 linked sialic acid, found on epithelial cells. Egg-based production is more likely to use a-2,3 linked sialic acid, which is less similar to the sialic acid of circulating influenza viruses.
Researchers have developed novel nanoparticle vaccines combining two major influenza proteins to protect mice from the virus. The vaccines contain the proteins hemagglutinin (HA) and neuraminidase (NA). The vaccines may one day be used as universal influenza vaccines. The researchers describe the vaccines in the journal Advanced Healthcare Materials.
The HA protein from four seasonal influenza virus strains was attached to protein nanoparticles. The resulting nanoparticle vaccine successfully elicited a strong immune response in nonhuman primates, mice, and ferrets. The researchers also found that their vaccine elicited the same immune responses as a commercial flu vaccine.
The new vaccines confer broad protection against the influenza virus. The new vaccines can be administered in a safe, effective way. Nanoparticles have increased the potency of influenza vaccines.
Next-generation COBRA design methodologies apply the in-silico design process to commercial vaccine production. This will enable the development of flu vaccines with real-time antigen production. Influenza vaccines have been on the market since the 1940s, but current vaccines are strain specific and have limited antigenic breadth.
COBRA methodology focuses on broadly reactive antigens. Previous COBRA designs focused on viruses from historical outbreaks and specific antigenic eras. The new method focuses on current circulating influenza viruses, and better represents the antigen diversity in those viruses. This approach has produced two promising next-generation H1N1 COBRA HA vaccine candidates.
The COBRA immunogen design methodology was applied to 22,144 human A(H3N2) viral amino acid sequences collected from January 1, 2002, to December 31, 2015. The COBRA methodology results in nine distinct Next Gen HA sequences, covering the influenza A(H3N2) virus isolates over multiple seasons.
COBRAs are computationally optimized broadly reactive antigens
COBRAs, or computationally optimized broadly reactive antigens, are synthetic HA antigens that induce protective antibodies against influenza viruses. Influenza A H1N1 is the only subclass of the influenza virus that has pandemic potential.
COBRAs can potentially reduce the selection bias associated with the antigens in a vaccine pool by optimizing antigen sequences based on multiple rounds. This new method allows vaccines to retain highly immunogenic epitopes and reduce cross-reactivity between influenza strains.
Seasonal influenza vaccines are the most effective tool for preventing influenza virus infections. However, seasonal influenza vaccines are limited in eliciting protective immune responses against multiple co-circulating influenza virus variant strains. To overcome this challenge, improved influenza virus vaccines must elicit protective immune responses against multiple drift variants of influenza viruses. The introduction of broadly reactive antigens may be a solution to this problem.
COBRA-derived H5 elicited broader protection than the wild-type clade 2.3.4.4A-derived H5. The COBRAs induced superior neutralizing antibody responses against diverse clades of the influenza virus.
A correlative approach to influenza vaccines focuses on how vaccines can be formulated to be effective against a wide range of flu viruses. Licensed vaccines contain three or four different virus strains, which must be reformulated annually according to global surveillance. Immunological correlates for vaccine effectiveness include the proportion of antibody titer neutralizing a particular influenza virus subtype or the balance of antibody titer specific to a strain.
This approach uses instrumental variable analysis to adjust for unmeasured confounding. This approach allows researchers to estimate vaccine effectiveness against various outcomes, including all-cause mortality, pneumonia, and hospitalization. The study also controls for underlying risk factors that may influence vaccination outcomes.
Although vaccines have a relatively high success rate, it is unclear whether they are effective in all age groups. In general, however, vaccination rates are higher in chronically ill and infirm adults than in public. In addition, the CDC recommends vaccination for healthy adults between the ages of two and 49. However, vaccine rates for healthy adults were below the baseline in 1998.
Depending on where you live and the type of vaccine you need, the cost of flu vaccines can vary significantly. Vaccines recommended for older adults are usually more expensive than those for younger people. However, there are ways to reduce costs, including shopping around or using a discount card like GoodRx. This program helps you save money on your annual flu vaccine by helping you find the best deal.
Many nonprofit organizations offer free or reduced-cost flu shots. The eligibility requirements vary from program to program, but generally, these programs are designed to help people who cannot afford a flu vaccine. In Connecticut, for example, the United Way of Southeastern Connecticut has a flu-shot program for uninsured and underinsured people. In Illinois, the DuPage Health Coalition offers flu shots to qualified families on a low income.
The District Health Department of Kent County in Michigan offers flu vaccine clinics. The vaccination costs range from $39 to $55. High-dose and preservative-free vaccines are both available. If you’re concerned about the price, you can visit the Health Department in Grayling. The health department accepts Blue Cross/Blue Shield and Blue Care Network.
New technologies could make it easier to create flu vaccines. For example, researchers are testing mRNA technology to make flu vaccines with circulating flu strains. But while that technology may help produce more effective flu vaccines, the mRNA vaccines also have some risks. Some scientists are concerned that this technology can lead to serious side effects.
Adjuvants are chemicals added to vaccine preparations to improve their effectiveness. These chemicals make flu vaccines more potent and protect people against more infections. These advances also mean that vaccines are more affordable, leading to higher vaccination rates. But are they worth the risks?
The current influenza vaccines have good safety and tolerability profiles but moderate efficacy. They induce protective immunity through antibodies to viral proteins, surface proteins, and hemagglutinin. However, the virus’s genetic makeup may be different in different individuals. This could pose a risk to recently received an influenza vaccine.