in london, greg alcott, fox news. >>> both pfizer and moderna say their vaccines appear to be effective against the new strains in the uk with four study still pending. officials say that despite the protein on the first notation which they used to infect human cells, is 99% similar to the protein on other strains that it is coded for. the meditation is 56 to 70% more transmissible than other virus strains in circulation. when asked to talk more about this is dr. john swarts bird from uc berkeley. thank you for joining us. i would just like to start off with moderna's and pfizer's claims that their vaccines are effective against these new strains. are you confident in that? >> i'm confident that is very likely. we need a lot more science right now and a lot less speculation about these viral strains and how effective vaccines will be. the reason i am confident it is likely is because the virus itself, even the ones that have changed in terms of their structure, are still sufficiently similar to what our vaccines tell our bodies to do in terms of immunity, to give us protection . i'm not