Self-administered inhaled zanamivir was used for a period of 5 days following enrolment. However, only 16% developed antibodies to the first dose of H1N1 vaccine and 61% after the second. Therefore, there are concerns that delays in SRID reagent availability could delay the availability of pandemic vaccines. Influenza viruses with reduced susceptibility to NA inhibitors have been isolated following sequential tissue culture passage of the virus in the presence of drugs. If a pandemic has started, however, it may be appropriate to give the vaccine to these patients, as long as facilities for resuscitation are available. a new subtype) which is serologically distinct from earlier viruses circulating in humans and could not have arisen from these viruses by mutation. Outbreaks of influenza B are less frequent and are associated with a lower burden of illness overall. The genetic basis for resistance appears to be single amino acid substitutions at positions 26, 27, 30, 31 or 34 in the transmembrane portion of the M2 ion channel 80. Schild and his colleagues were able to produce very potent antisera to purified HA in goats and rabbits and demonstrated that the antisera reacted well with HA released from detergent‐disrupted influenza virus in agarose gels.8, 10 They also worked out some of the key parameters of the assay including the influence of antigen and antiserum concentration, antigenic specificity of the assay and within‐laboratory reproducibility.10, As SRID and IEP were new techniques, it was important that other laboratories acquired the technologies and that the results from different laboratories were in agreement. This ensures that the assay is very robust and can be used in any laboratory, irrespective of their resources.

Eur Respir J 2001; 17: 995–1007.

During the first year of the study, 1,314 healthy children aged 15–71 months received a 2-dose regimen of trivalent CA reassortment vaccine. The antiviral spectrum and clinical effectiveness of zanamivir included both influenza A and B virus infections. of oseltamivir. It contains a flu strain called A/Viet Nam/1194/2004 (H5N1).

Eur Respir J 2001; 17: 295–301. As it is likely that SRID will remain the primary potency assay for inactivated influenza vaccines for the foreseeable future, efforts should be made to improve the assay, including: Harmonisation of assay method and reagent availability. ↵Previous articles in this series: No. Start typing to retrieve search suggestions. In 1997, the SRID assay was accepted for influenza vaccine potency testing in the EU by the EU Committee for Medicinal Products for Human Use (CHMP)18 and it was desirable to maintain proficiency of EU laboratories by regular evaluation. Reverse‐phase high‐performance liquid chromatography (RP‐HPLC) is another commonly used technique for quantifying HA,30, 31 particularly during manufacturing in‐process testing. Furthermore, it is likely that a huge number of doses of pandemic vaccine will be needed and thus more reagents than normal will be needed to test the vaccines.

In contrast, live vaccines use pathogens that are still alive (but are almost always attenuated, that is, weakened). The feasibility of stockpiling SRID antisera in preparation for a pandemic has recently been suggested,23 and some progress in this direction has already been made.24 Another possibility to improve reliability of antiserum production is to use recombinant HA derived from suitable viral or bacterial vectors.25. Pandemic Influenza Vaccines: What did We Learn from the 2009 Pandemic and are We Better Prepared Now?. When symptomatic, influenza typically produces an acute febrile illness characterized by cough, headache and myalgia. Improvement of the reagent calibration process. All medicines, including vaccines, have risks and benefits. As the examples above hopefully demonstrate, remarkable progress has been made in development and evaluation of new influenza vaccine potency assays that may address some of the shortcomings of the current SRID assay. For afebrile patients, no benefit was observed and there was no difference between influenza A and B virus infections. many of those in the higher risk groups for influenza. Twenty participants from the vaccine industry and regulatory agencies went “back to school” and learned how to run both assays. Thus, the foundations were laid for a significant change in the way that influenza vaccines were standardised. It is given by injection into the upper arm muscle or the thigh. One of the problems associated with the use of current inactivated vaccines is the need to give repeated annual injections. In July 2010, an important meeting jointly organised by Health Canada, the United States Food and Drug Administration (FDA), and the WHO was held in Ottawa, Canada, to assess the lessons learned from potency testing of 2009 H1N1 pandemic vaccines.27 Some of the key conclusions were as follows: A substantial amount of work has been undertaken, both before and since the Ottawa meeting, to develop and evaluate the feasibility of alternative methods for potency determination. A formal health-economic study is needed to address these concerns 109. VaxArray for hemagglutinin and neuraminidase potency testing of influenza vaccines, http://www.ema.europa.eu/docs/en_GB/document_library/Scientific_guideline/2009/09/WC500003945.pdf, http://www.who.int/influenza/vaccines/virus/en/Accessed, http://www.ema.europa.eu/docs/en_GB/document_library/Scientific_guideline/2014/06/WC500167817.pdf.